It is well-known to provide manholes, such as for example in road and pavement surfaces, for providing access to underground services and installations. For example, for the purpose of providing access to underground electrical, telephone, plumbing and sewerage services and installations. These are by way of example only. Such manholes include frames which are normally set in concrete or some other settable material, and are positioned substantially flush with a road or pavement surface. Covers are provided for such frames and fit within the open upper end of said frames so as to again be substantially flush with the road or pavement surface.
It will be appreciated however, that in the case of many road or pavement surfaces, resurfacing is required from time to time. For example, typically a city road may be resurfaced by applying a further layer of surface material on top of an existing surface material. For example, by applying a 40 mm thick layer of surface material on top of an existing surface.
It will therefore be appreciated that when such an existing surface is resurfaced, the upper surface of the road or pavement will be above the upper surface of the original or existing manhole frame and cover. Clearly, this is unacceptable, and it is therefore necessary to provide an arrangement and method whereby the manhole cover frame and cover can be raised above the original height thereof, so as to be substantially flush or normal with the upper surface of the new or resurfaced layer of surface material.
Up until this time, manhole cover frames have often been raised by digging the frame out of its concrete setting, and lifting it to the appropriate level and resetting it in concrete relative to the new raised surface of the road or pavement. This has however been found to be inefficient, time consuming and expensive. Other arrangements and methods have also been proposed, but these have been generally found to be unsatisfactory and inefficient.
The present invention sets out to provide an arrangement and method for use in raising the height of manhole cover frames, relative to a new surface of for example a road or pavement, which go at least some way towards overcoming or minimising the problems and disadvantages with such arrangements and methods known and used up until this time.
Other objects of this invention will become apparent from the following description.